1. Field of the Invention
This invention relates to a refrigerator-freezer provided with two evaporators, that is, a first evaporator for cooling an atmosphere in a refrigerating compartment and a second evaporator for cooling an atmosphere in a freezing compartment.
2. Description of the Prior Art
There have conventionally been provided refrigerator-freezers in which a liquid refrigerant having passed through a compressor and a condenser is further supplied to an evaporator to be evaporated such that the evaporator is cooled. A cold air produced by the evaporator is supplied to a freezing compartment by a blower so that an atmosphere in the freezing compartment is cooled and so that the cold air is also supplied to a refrigerating compartment via a damper so that an atmosphere in the refrigerating compartment is cooled. When a temperature in the refrigerating compartment drops to a lower limit temperature (for example, 1.degree. C.), the damper is closed so that the supply of cold air to the refrigerating compartment is interrupted. When the temperature in the refrigerating compartment increases to an upper limit temperature (for example, 5.degree. C.), the damper is opened so that the supply of cold air to the refrigerating compartment re-started. As a result, the temperature in the refrigerating compartment is controlled so as to be maintained at a predetermined temperature (for example, 3.degree. C.). Further, the operation of the compressor is stopped when a temperature in the freezing compartment drops to a lower limit temperature (for example, -22.degree. C.). The operation of the compressor is re-started when the temperature in the freezing compartment increases to an upper limit temperature (for example, -18.degree. C.). As a result, the temperature in the freezing compartment is controlled so as to be maintained at a predetermined temperature (for example, -20.degree. C.).
In the above-described refrigerator-freezer, however, the operation of the compressor is automatically stopped when the temperature in the freezing compartment drops to the lower limit temperature as described above. Accordingly, the operation of the compressor may be stopped even when the temperature in the refrigerating compartment is relatively high. In such a case, when the temperature in the freezing compartment thereafter increases to the upper limit temperature such that the operation of the compressor is re-started, the temperature in the refrigerating compartment exceeds the upper limit temperature. Accordingly, thereafter, it takes a lot of time for each of the temperatures in the respective refrigerating and freezing compartments to drop to the corresponding preset temperature. This results in a reduction in the operating efficiency of the compressor, whereupon food cannot be cooled efficiently.